Biochemist in Spain retracts eight papers at once

Carlos López-Otín

A high-profile researcher at the Universidad de Oviedo in Spain has retracted eight papers from the Journal of Biological Chemistry for figure issues.

All of the papers were co-authored by Carlos López-Otín, who studies a group of enzymes that break down proteins, cancer genomics and aging, and whose lab web site boasts that

His works have been collected in more than 400 articles in international journals and have been cited to date more than 44.000 times, with an aggregate Hirsch index of h=100.

A representative notice:

This article has been withdrawn by the authors upon request from the Journal. The Journal raised questions regarding Fig. 4, A and B. The authors were able to locate the original autoradiographs corresponding to Fig. 4A, detecting two duplicated GAPDH control bands. In Fig. 4B, an actin lane appears to be duplicated. Since the original data for the experiment shown in Fig. 4B, performed 13 years ago, could not be found, the authors state that a new experiment was performed using RNA from mouse testis from different ages (10–74 days). The authors state that the AP-O expression results concur with an RNA-seq–based transcriptomic analysis reported independently by other researchers (Margolin et al. (2014) BMC Genomics 15, 39). The authors assert that all of the results reported in this article are valid.

López-Otín told Retraction Watch that

those articles contained some faults in specific panels that did not affect any of the conclusions of the study. We were not aware of the existence of those errors until the journal contacted us. When we realized about these issues, we sent the journal the original images, showing that the original data fully supported the results presented in those figures. In some cases in which original data was not available, as most articles were published more than 14 years ago, our lab repeated those experiments, obtaining the same results.

López-Otín’s team asked for a correction, but the JBC said that wouldn’t be sufficient:

Therefore, we acknowledged those mistakes for which we feel embarrassed, and even though they affected minor figure panels, with no effect on the main message of the article, we requested the journal to publish a correction. Unfortunately, when dealing with these issues, JBC does not take into account whether the study is valid or whether it had been reproduced by the authors or other groups, and they requested from us to withdraw the articles.

López-Otín told us that “there are no more questioned articles.”

The eight papers, which were originally published between 2000 and 2007, are:

López-Otín tells us:

These studies described the identification of novel protease-coding genes, and their preliminary characterization as proteolytic enzymes. There is no doubt in the scientific community that these human genes exist and have the nucleotide and amino acid sequences we had reported in these articles, that they are expressed in the tissues we showed, and that they constitute proteolytic enzymes. Therefore, the findings reported in these articles have been widely validated by the scientific community, with more than 800 citations altogether.

Does López-Otín think the retractions were warranted?

[I]f the results reported in an article are true, the experiments can be reproduced, and the findings have been validated by the scientific community, a retraction is harmful both for Science and for the scientists. Should a correction have been published: no doubt about it. The articles are very old, the results validated, but if a mistake is found and it can be corrected, we the authors are the first ones to have an interest in fixing any error that might be present in our publications.

Another of López-Otín’s papers, this one in Nature Cell Biology, was retracted last month:

We, the authors, are retracting this Article due to issues that have come to our attention regarding data availability, data description and figure assembly. Specifically, original numerical data are not available for the majority of the graphs presented in the paper. Although original data were available for most EMSA and immunoblot experiments, those corresponding to the published EMSA data of Supplementary Fig. 8a, the independent replicate immunoblots of Fig. 8b and Supplementary Fig. 1e, and the independent replicate EMSA data of Supplementary Figs 6e, 8b, 8c and 8d, are unavailable. Mistakes were detected in the presentation of Figs 3c, 4i and Supplementary Figs 6a, 8a, 8d, 9, and in some cases the β-actin immunoblots were erroneously described in the figure legends as loading controls, rather than as sample processing controls that were run on separate gels. Although we, the authors, believe that the key findings of the paper are still valid, given the issues with data availability we have concluded that the most appropriate course of action is to retract the Article. We deeply regret these errors and apologize to the scientific community for any confusion this publication may have caused. All authors agree with the retraction.

One of the authors of that paper, George Q. Daley, is now dean of Harvard Medical School. The paper has been cited 53 times.

Like Retraction Watch? You can make a tax-deductible contribution to support our growth, follow us on Twitter, like us on Facebook, add us to your RSS reader, sign up for an email every time there’s a new post (look for the “follow” button at the lower right part of your screen), or subscribe to our daily digest. If you find a retraction that’s not in our database, you can let us know here. For comments or feedback, email us at

25 thoughts on “Biochemist in Spain retracts eight papers at once”

  1. Cancer Res. 2000 Feb 15;60(4):877-82.
    Human MT6-matrix metalloproteinase: identification, progelatinase A activation, and expression in brain tumors.
    Velasco G1, Cal S, Merlos-Suárez A, Ferrando AA, Alvarez S, Nakano A, Arribas J, López-Otín C.
    Author information
    Departamento de Bioquimica y Biologia Molecular, Facultad de Medicina, Universidad de Oviedo, Spain.


  2. BMC Biochem. 2006 Mar 27;7:9.
    Identification and characterization of human polyserase-3, a novel protein with tandem serine-protease domains in the same polypeptide chain.
    Cal S1, Peinado JR, Llamazares M, Quesada V, Moncada-Pazos A, Garabaya C, López-Otín C.
    Author information
    Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Oncología, Universidad de Oviedo, 33006-Oviedo, Spain.


    1. Those image manipulation “shown” there is not true at all, how easy destroying someone’s reputation gain with lot of hard hard work… there was a honest flip of a bloddy actin loading blot from commercial northern blots, irrelevant, there’s no quantification, there’s presence or absence of the gene in those tissues…

    1. Not various figure issues, but wrong labeling of a commercial northern blot for actin loading, there was no necessity showing once and again the loading control, we could have referred to older articles, our interest at the time when no human genome sequence was available was identifying and amplifying new protease coding genes in the appropriate tissue where they were expressed. No alterations, no manipulation, honest unnecessary mistake (propagated due to miss labeling of the actin RNA blot). I am working in Science for almost 20 years, 3 different countries, 7 different labs, never met such a generous, meticulous and honest scientist as Prof. Lopez-Otin. No need to be spread, but personal prizes were always donated to charity, always time for patients, scientists, students… don’t know who’s hunting but not fair at all. And again, if mistakes that do not alter results or messages are done, why can’t they be corrected? Does it mean now those genes do not exist?

  3. Researchers should support JBC. Their strict zero tolerance policy is the only way to go in order to increase the trust and reproducibility in scholarly literature.

    So called “reproduced” in the original lab or submitting some new images that could be everything, doesn’t help. If some of your friends are reproducing your manipulations, so what? Faulty research results are surprisingly often “reproduced”.

    Articles containing manipulations should be retracted without discussions, especially if there several problematic issues.

    1. “Their peer review and editorial scrutiny failed.”
      For the original publications, but now they have retracted them.

  4. Nature. 2005 Sep 22;437(7058):564-8. Epub 2005 Aug 3.
    Accelerated ageing in mice deficient in Zmpste24 protease is linked to p53 signalling activation.
    Varela I1, Cadiñanos J, Pendás AM, Gutiérrez-Fernández A, Folgueras AR, Sánchez LM, Zhou Z, Rodríguez FJ, Stewart CL, Vega JA, Tryggvason K, Freije JM, López-Otín C.
    Author information
    Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Instituto Universitario de Oncología, Universidad de Oviedo, 33006 Oviedo, Spain.

    Figures 1b and 2f. Much more similar than you would expect.


  5. If a careful, conscientious lab repeated a whole lot of its earlier experiments with new reagents, equipment, strains, etc. that are now available, I don’t think they’d usually get 100% replication. They’d get a decent amount, but there’s generally some error factor in experimental science.

    It therefore seems deeply problematic that labs which falsify their figures and then (claim to) repeat the experiments would ALWAYS completely confirm their original findings. And yet I can’t think of a counterexample.

    I would totally have retracted these papers.

  6. University of Oviedo threatening legal action? What is its case?

    “Oviedo.-La Universidad de Oviedo, por boca de su rector, Santiago García Granda, cerró filas este lunes en torno al investigador Carlos López Otín, algunos de cuyos artículos fueron cuestionados en una “extraña maniobra” secundada anónimamente en las redes sociales. La Universidad asturiana anuncia, así mismo, acciones judiciales “para preservar el buen nombre y reputación de nuestra institución, así como en defensa al derecho al honor y la propia imagen de las y los miembros de nuestra comunidad universitaria en el ejercicio de sus labores investigadoras, docentes y de gestión.”

    “Oviedo.-The University of Oviedo, through the mouth of its rector, Santiago García Granda, closed ranks on Monday around the researcher Carlos López Otín, some of whose articles were questioned in a “strange maneuver” anonymously seconded on social networks. The Asturian University also announces legal actions “to preserve the good name and reputation of our institution, as well as in defense of the right to honor and the image of the members of our university community in the exercise of their investigative work. , teachers and management. ”

    “En todo caso, la Universidad de Oviedo se reserva su derecho a emprender acciones judiciales para preservar el buen nombre y reputación de nuestra institución, así como en defensa al derecho al honor y la propia imagen de las y los miembros de nuestra comunidad universitaria en el ejercicio de sus labores investigadoras, docentes y de gestión.”

    “In any case, the University of Oviedo reserves the right to take legal action to preserve the good name and reputation of our institution, as well as in defense of the right to honor and the image of the members of our university community in the exercise of their research, teaching and management tasks.”


    “Más de 50 científicos defienden la validez del trabajo de López Otín tras la retirada de ocho de sus artículos”

    “More than 50 scientists defend the validity of López Otín’s work after the withdrawal of eight of his articles”

    “Los errores detectados no afectan de ninguna manera a las conclusiones de las investigaciones, que han sido validadas de forma independiente en múltiples ocasiones y han servido de base para otros trabajos, como el desarrollo de modelos animales para entender la progresión del cáncer. Nadie duda de su validez”, subraya el investigador.
    Junto a él, firman la carta personalidades de primer nivel en el ámbito de la ciencia como Margarita Salas, profesora Ad Honorem del Centro de Biología Molecular Severo Ochoa; Manuel Serrano, investigador del IRB de Barcelona; Elías Campo, científico del Instituto de Investigaciones Biomédicas Augus Pi i Sunyer de Barcelona; Cristina Garmendia, ex ministra de Ciencia; José López-Barneo, del Instituto de Biomedicina de Sevilla o Juan Bueren, del Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas de Madrid, entre otros.”

    “The errors detected do not affect in any way the conclusions of the investigations, which have been validated independently on multiple occasions and have served as the basis for other works, such as the development of animal models to understand the progression of cancer. of its validity “, emphasizes the researcher. Next to it, the letter signed personalities of first level in the field of science as Margarita Salas, professor Ad Honorem of the Severo Ochoa Molecular Biology Center; Manuel Serrano, researcher at the IRB of Barcelona; Elías Campo, a scientist at the Augus Pi i Sunyer Biomedical Research Institute in Barcelona; Cristina Garmendia, former Minister of Science; José López-Barneo, of the Institute of Biomedicine of Seville or Juan Bueren, of the Center for Energy, Environmental and Technological Research of Madrid, among others.”

  8. The leader of the Asturian Government and The Minister of Health of the Government of the Principality of Asturias, Francisco del Busto, speak in support of Carlos López Otín.

    “El consejero de Sanidad del Gobierno del Principado de Asturias, Francisco del Busto, ha tenido este jueves palabras de apoyo para el investigador y catedrático en el área de Bioquímica y Biología Molecular en el departamento de Bioquímica de la Universidad de Oviedo, Carlos López Otín (Sabiñánigo, Huesca, 1958).”

    “The Minister of Health of the Government of the Principality of Asturias, Francisco del Busto, this Thursday has words of support for the researcher and professor in the area of ​​Biochemistry and Molecular Biology in the Department of Biochemistry of the University of Oviedo, Carlos López Otín ( Sabiñánigo, Huesca, 1958).”

    “”Pienso de todo corazón que la categoría científica pero también humana de Carlos López Otín, está por encima de las dudas intencionadas que se han suscitado en torno a una pequeña parte de su enorme contribución a la ciencia y que el propio profesor Otín se encargará de aclarar y explicar suficientemente”, ha dicho Del Busto en una intervención que ha realizado en la II Jornada de innovación de la Fundación para la Investigación y la Innovacion Biosanitaria (Finba) – Instituto de Investigación Sanitaria de Asturias (ISPA).”

    “”I think with all my heart that the scientific but also human category of Carlos López Otín, is above the intentional doubts that have arisen around a small part of his enormous contribution to science and that Professor Otín himself will take care of clarify and explain sufficiently, “Del Busto said in an intervention that has made in the II Conference of innovation of the Foundation for Research and Innovation Biosanitaria (Finba) – Health Research Institute of Asturias (ISPA).”

    “En su discurso, el consejero asturiano ha querido que su primer mensaje se para “uno de los nuestros”, en referencia a Otín, al que ha calificado como “una de las figuras más insignes de la investigación de excelencia que ha dado nuestro país, un referente internacional en su campo, un científico de primer orden que es un verdadero lujo para la Universidad de Oviedo pero también para el conjunto de la sociedad asturiana y que, nos consta a todos, está pasando unos momentos difíciles”.”

    “In his speech, the Asturian councilor wanted his first message to be “one of ours”, in reference to Otín, whom he has qualified as “one of the most distinguished figures of the research of excellence that our country has given, an international benchmark in his field, a first-rate scientist who is a true luxury for the University of Oviedo but also for the whole of Asturian society and that, we all know, is having a difficult time. “”

    “El dirigente del Gobierno asturiano ha dicho que espera que el reconocimiento a Carlos López Otin sirva también para ilustrar en qué medida el mundo de la investigación científica de calidad, de la innovación, de la excelencia, es un campo enormemente “competitivo y apasionante”, que conjuga “diversos intereses de todo tipo”, pero que es “un enorme motor de progreso porque en este ámbito de la investigación médica más avanzada se están manejando algunas de las claves del progreso, de nuestro devenir como especie, del desarrollo individual de muchísimas personas, pero también del futuro de la humanidad”.

    “The leader of the Asturian Government has said that he hopes that the recognition of Carlos López Otin will also serve to illustrate to what extent the world of scientific research of quality, innovation, excellence, is a hugely “competitive and exciting” field, which combines “diverse interests of all kinds”, but which is “an enormous engine of progress because in this area of ​​the most advanced medical research some of the keys of progress, of our becoming as a species, of the individual development of many people, but also the future of humanity. “”


    “Asociación para la Transparencia pide explicaciones claras y rigurosas a la Universidad de Oviedo y a Otín”.

    “Association for Transparency calls on University of Oviedo for clear and rigorous explanations Otín”

    “Consideran que el ‘cierre de filas’ que se está produciendo puede generar más dudas”

    “They consider that the ‘closing of ranks’ that is taking place can generate more doubts”


    “La Universidad de Oviedo ya negó irregularidades de López-Otín en 2017 Lo hizo por medio de carta a un ciudadano que había planteado dudas sobre sus trabajos”

    “The University of Oviedo has already denied irregularities of López-Otín in 2017 It did so by means of a letter to a citizen who had raised doubts about his work”.

    “La Universidad de Oviedo negó el 30 de octubre de 2017 la existencia de irregularidades en diferentes artículos científicos en los que había participado como autor Carlos López Otín como catedrático en el área de Bioquímica y Biología Molecular en el departamento de Bioquímica de la Universidad de Oviedo.

    Así consta en una carta con el sello de la Universidad firmada por el vicerrector de Investigación de la Universidad de Oviedo, José Ramón Obeso, dirigida a un ciudadano que había planteado dudas acerca de los artículos.

    En la misiva, Obeso explica que el Comité de Ética de Investigación de la Universidad de Oviedo estudió el asunto y, tras escuchar a “expertos en la materia”, concluyó que no existen “irregularidades relevantes en los artículos que menciona y la investigación se ha desarrollado siguiendo los estandares establecidos por las diferentes publicaciones”.

    Además, Obeso añadió en la carta el “apoyo expreso” de la Universidad de Oviedo a Carlos Otín y a su grupo de investigación, añadiendo que en la institución estaban muy preocupados “por las consecuencias potenciales de publicar ese tipo de dudas en Internet”.

    “The University of Oviedo denied on October 30, 2017 the existence of irregularities in different scientific articles in which Carlos López Otín had participated as a professor in the area of ​​Biochemistry and Molecular Biology in the Department of Biochemistry of the University of Oviedo.

    This is stated in a letter with the seal of the University signed by the Vice Chancellor for Research of the University of Oviedo, José Ramón Obeso, addressed to a citizen who had raised doubts about the articles.

    In the letter, Obeso explains that the Research Ethics Committee of the University of Oviedo studied the matter and, after listening to “experts in the field”, concluded that there are no “relevant irregularities in the articles mentioned and the investigation has been developed following the standards established by the different publications “.

    In addition, Obeso added in the letter the “express support” of the University of Oviedo to Carlos Otín and his research group, adding that in the institution they were very concerned “about the potential consequences of publishing such doubts on the Internet.””

    “La carta no se publicó hasta ahora

    La carta no se hizo pública entonces. Fue la semana pasada, casi año y medio después, cuando ha trascendido la retirada de nueve artículos entre cuyos autores figura López Otín. En concreto, fue retirado en octubre un ‘paper’ publicado en 2015 de la revista ‘Nature Cell Biology’ tras detectarse irregularidades en algunas imágenes. Más recientemente otros ocho artículos en los que ha participado el investigador, publicados entre 2007 y 2009, también fueron retirados en su totalidad por los mismos motivos por sus autores, a requerimiento de la revista Journal of Biological Chemistry.

    Desde la Universidad de Oviedo se emitió un comunicado de tres párrafos en apoyo de López Otín, quien se encuentra realizando una estancia sabática de seis meses en París. Posteriormente añadieron que Otín se reincorporará próximamente a la Universidad de Oviedo y declinaron dar más detalles ni responder a preguntas, alegando que habían facilitado ya “amplia información”.

    Por su parte, López Otín dijo que la retirada de ocho de sus artículos de la revista ‘Journal of Biological Chemistry’ resulta “dañino tanto para la ciencia como para los científicos”, ya que se trata de publicaciones “muy antiguas” y sus resultados están “ampliamente validados” y “no tenían ningún impacto sobre el mensaje principal del artículo”.

    “The letter was not published until now

    The letter was not made public then. It was last week, almost a year and a half later, when it has transpired the withdrawal of nine articles whose authors include López Otín. Specifically, in October a ‘paper’ published in the magazine ‘Nature Cell Biology’ was removed in October after detecting irregularities in some images. More recently, eight other articles in which the researcher has participated, published between 2007 and 2009, were also withdrawn in their entirety for the same reasons by their authors, at the request of the Journal of Biological Chemistry.

    From the University of Oviedo, a three-paragraph statement was issued in support of López Otín, who is on a six-month sabbatical in Paris. They later added that Otín will soon rejoin the University of Oviedo and declined to give more details or answer questions, claiming that they had already provided “extensive information”.

    For his part, Lopez Otín said that the withdrawal of eight of his articles in the journal ‘Journal of Biological Chemistry’ is “harmful to both science and scientists,” since they are “very old” publications and their results they are “widely validated” and “had no impact on the main message of the article”.”

    “5.000 ratones sacrificados

    En una entrevista concedida al diario asturiano La Nueva España la pasada semana, López Otín, reveló que más de 5.000 ratones con los que investigaba habían tenido que ser sacrificados hace unos meses por culpa de una infección “sin precedentes”. Explicaba además que era objeto desde hace tiempo de una campaña de acoso.

    Tras esa revelación, la Universidad de Oviedo confirmó mediante una escueta nota que hace unos meses se detectó en el Bioterio de la institución un brote infeccioso con un virus murino. “Con objeto de erradicar la infección, se procedió al desalojo de las instalaciones, a su limpieza en profundidad y a su esterilización”, se han limitado a declarar sobre lo sucedido, sin querer aclarar más detalles sobre lo ocurrido.

    Para distintos miembros de la comunicad científica e investigadora las explicaciones no están siendo suficientes. La Asociación Transparencia Universitaria (ATU) advertía esta semana que el ‘cierre de filas’ que se estaba produciendo podía ser contraproducente y generar aún más dudas.

    En un comunicado han solicitado que se ponga fin al “oscurantismo” y han anunciado que solicitarán formalmente la información sobre el caso y los procesos de experimentación animal, tanto al propio investigador López Otín y a la Universidad de Oviedo, concretamente al Vicerrectorado de Investigación, a la Comisión de Bioética y al Comité de Ética de la Investigación de la propia Universidad.”

    “5,000 sacrificed mice

    In an interview with the Asturian newspaper La Nueva España last week, López Otín revealed that more than 5,000 mice with which he was investigating had to be slaughtered a few months ago because of an “unprecedented” infection. He also explained that he had been the target of a harassment campaign for some time.

    After that revelation, the University of Oviedo confirmed by means of a brief note that a few months ago an infectious outbreak with a murine virus was detected in the Bioterio of the institution. “In order to eradicate the infection, we proceeded to evict the facilities, to clean them thoroughly and to sterilize them”, they have limited themselves to declaring what happened, without wanting to clarify more details about what happened.

    For different members of the scientific and research community the explanations are not enough. The University Transparency Association (ATU) warned this week that the ‘closing of ranks’ that was taking place could be counterproductive and generate even more doubts.

    In a statement they have requested that the “obscurantism” be stopped and they have announced that they will formally request information on the case and the processes of animal experimentation, both to the researcher López Otín and the University of Oviedo, specifically to the Vice-Rector for Research, the Bioethics Commission and the Research Ethics Committee of the University itself.”

  11. “López-Otín told us that “there are no more questioned articles.””

    I think he means no more questioned articles in the Journal of Biological Chemistry.

    There are other articles which have been questioned.


    “La presidenta del CSIC defiende a Otín afirmando que se está “arremetiendo contra un científico de forma injusta””

    “The president of the CSIC defends Otín stating that he is “attacking a scientist unfairly””


    La presidenta del Centro Superior de Investigaciones Científicas (CSIC) ha defendido este viernes al investigador de la Universidad de Oviedo Carlos López Otín al afirmar que se está “arremetiendo contra un científico de forma injusta”.

    Así lo ha afirmado en Oviedo, durante la firma de un acuerdo entre CSIC y el Instituto de Investigación Sanitaria de Asturias, donde a preguntas de los medios se ha posicionado sobre la polémica surgida en la comunidad científica en las últimas semanas después de que a Otín le fueran retirados nueve artículos en dos revistas científicas.

    En ese sentido, Menéndez ha calificado de “triste” que “las cosas se demuestren con el paso del tiempo” y que mientras tanto “se viven situaciones violentas”, como se cuestione a un científico por unos “detalles concretos” que, además, está explicando.

    Por todo ello, ha mostrado su respeto por Otín y ha afirmado que “arremeter contra un científico de una forma injusta no es el camino”. “Afecta a la vida personal, no hay que ensañarse”, ha demandado, para mostrar públicamente “todo su apoyo”.

    También ha querido mostrar su apoyo al científico el consejero de Sanidad asturiano, Francisco del Busto, que ha defendido la labor investigadora de Carlos Otín a lo largo de décadas. “El ya ha demostrado a lo largo de su vida lo que ha aportado a la ciencia”, ha sentenciado, para añadir que tendrá que ser la parte de la comunidad científica que está poniendo en duda sus investigaciones la que debe de “desagraviarse”.”


    The president of the Higher Center for Scientific Research (CSIC) has defended this Friday the researcher of the University of Oviedo Carlos López Otín to say that he is “attacking a scientist unfairly.”

    This has been said in Oviedo, during the signing of an agreement between CSIC and the Health Research Institute of Asturias, where questions from the media has positioned itself on the controversy that arose in the scientific community in the last weeks after Otín nine articles were withdrawn in two scientific journals.

    In that sense, Menéndez has described as “sad” that “things are proven over time” and that meanwhile “violent situations are experienced”, as a scientist is questioned by “concrete details” that, in addition, is explaining.

    For all these reasons, he has shown his respect for Otín and has affirmed that “attacking a scientist in an unjust way is not the way”. “It affects the personal life, it is not necessary to be insane”, has demanded, to publicly show “all his support”.

    He also wanted to show his support to the scientist the Asturian Health Minister, Francisco del Busto, who has defended the research work of Carlos Otín over the decades. “He has already demonstrated throughout his life what he has contributed to science”, he has sentenced, adding that it will be the part of the scientific community that is questioning his research that should “be redressed”.”

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.